Thermal shock behaviour of α:β-SiAlON-TiN composites

Abstract

alpha:beta-SiAlON and 10, 17, and 25 wt% TiN particle reinforced composites were produced by a gas pressure sintering method. The densification behavior, phase and microstructural evolution, mechanical and thermal shock behavior of materials were investigated. The TiN incorporation had significant influence on the matrix microstructure and improved fracture toughness of the material. The highest fracture toughness was obtained for the composite with 25 wt% TiN (K-1c: 8.2 +/- 0.2 MPa m(1/2)). SiAlON-TiN composites showed lower crack formation and propagation compared to the monolithic SiAlON. Above 700 degrees C passive oxidation took place and provided crack healing by filling the cracks with TiO2, and the thermal shock resistance behavior was improved. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.